THE RIVER’S TURN

• Published date: 15 July 2023
• Publication title: Mix, The

High up between hills, on the banks of the Manuherikia River in the northern reaches of Central Otago, sits the tiny town of Omakau. On a cold winter’s day with a hoar frost, its cosy cafe is a blessing. Four local grandmothers and firm friends, Ruth, Margaret, Rona and Monica sit in the warmth and chat

When asked how many children, grandchildren and great grandchildren they have between them, they run out of fingers and the precise number proves elusive. It is a lot. They reminisce about summers in the 1960s, by the river with their families.

‘‘We used to take picnics after lunch, with half a gallon of cordial and biscuits — they were wonderful times,’’ says Ruth Kilkelly, 82 and mother of seven. There used to be a rope swing, but the river in summer can be too low for that now. The women talk of ‘‘sludgy’’ water — but don’t want to talk about the whys and wherefores. They leave that to the younger folk who run things around here.

The Manuherikia River starts, like many rivers, spectacularly — in the hills of Oteake Conservation Park near the Canterbury border. It flows in wide braids across a high plateau, before descending to a catchment of two parallel valleys — the Manuherikia and Ida valleys.

Flowing past Omakau in the Manuherikia valley, it ends at Alexandra in the southwest, where it joins the Clutha river.

The river’s journey is through a unique, desert climate, with cold winters and hot summers. There is limited rainfall at the headwaters and less — about 400mm a year — in the valleys below. Moisture quickly evaporates.

‘‘You can touch the soil, lick your finger and taste the salt,’’ says Matt Sole, secretary of the Central Otago Environmental Society (COES).

Once cloaked in diverse forest and shrubland with, surprisingly, some wetlands, this is still a special place with endangered species, explains Sole, including a rare tree daisy and the pārera — grey duck. The river is home to kōura — crayfish — and non-migratory galaxias, an ancient, scaleless fish .

The river and its catchment, however, have a distinctly human modern history. Before entering the two valleys, the river is caught in a small dam — Falls Dam — built in the 1930s and nearing its life-expectancy. Water is then released below into a pretty gorge.

The dam is one piece of a bigger, complex, jigsaw of irrigation infrastructure and irrigators, stretching across the catchment and dependent on the river and its many tributary creeks.

Across the Manuherikia and Ida valleys there are dams and races channelling water from the creeks and the river, mostly to irrigate grass and crops to feed animals. More than eight in 10 hectares in the 303,000ha catchment are used for livestock farming. Water storage ponds and bore holes also dot the landscape.

In summer, the river has least water to give, just when the valley’s irrigators are most dependent on it. Among them, are farmers who have invested significantly in modern irrigation equipment and farming business plans reliant on the continuation of permits allowing large water abstraction.

Farm irrigation in the Manuherikia and Ida valleys goes way back. In 1909, a government report supported water allocations to farmers to make ‘‘idle land’’ productive to ‘‘an incredible degree’’. Farmers were demanding ‘‘give us water and the future is assured’’. The farmers meant a future for their businesses and a community. They were granted huge water allocations, that had originally been used for gold mining. The irrigation infrastructure was built.

Farming hasn’t stood still. An 1884 flour mill in the Ida Valley is now a converted home. Families farming sheep and beef cattle stayed for generations, irrigating. Omakau became a community and survived, despite the railway closing. The Otago Central cycle trail replaced the trains.

Sheep and beef cattle farming dominates here but dairy has taken a minority position, the first dairy platform established near Omakau in 2009. Dairy farmland increased more than 100-fold between 2008 and 2022 — from 20ha to 2241ha. Dairy support — grazing calves and cows for the dairy industry, including wintering of dairy herds, occupies another 3420ha.

There is agreement the dry climate is good for cows’ health. Pugging — wet pastures churned by cattle — is low risk. A dairy cow, however, can drink as much water as 30 lambs on a dry pasture. Beef cattle drink as much as 20 lambs. Irrigated cattle farming also means significant risk of river pollution due to fertiliser and faeces run-off.

One sheep farmer, not wanting to be named, says: ‘‘It’s a matter of profits. It costs more to shear my sheep than I get for wool. Dairy farmers have been buying adjacent paddocks for grazing — and will swallow up my land if I sell. I won’t comment on their practices.’’

He adds: ‘‘This is a fragile environment. It requires gentle farming. I farm in a way that sits best with my conscience. There are others, like me, just getting by on the old methods.’’

Despite the irrigation infrastructure, not every farmer here irrigates. Hamish Cameron’s 4000ha ‘‘dry’’ farm, near Falls Dam, gets a little more rain than the farms further down the valleys. He only uses the river to supply drinking troughs for his sheep and cattle. In the driest times, he runs fewer stock. It is traditional farming. ‘‘The old boys weren’t stupid,’’ he says.

Below Cameron it is also possible to ‘‘dry’’ farm. In the Ida Valley, Barney Dundass has farmed sheep since 1962, without irrigation, on his 484 hectares at Moufeyvale farm. He dry-farms 3000 ewes and 600 hoggets. Lambs leave before they are six months, to limit water use.

The Ida Burn flows through his land. Only it doesn’t — in summer. It is ‘‘completely dry’’ for 5km, he says. His neighbours are irrigating farmers.

‘‘The creek stops when the irrigators start,’’ Dundass says, sounding factual, not...